This invention relates to a guide indication method in an onboard navigator which performs optimum route guiding or route instruction for a vehicle, and relates particularly to a guide indication method in an onboard navigator which reports by an arrow or by a voice which of the right and left directions to go when the vehicle enters into a road from outside the road, such as from a parking lot, or the like.
Generally, the system of an onboard (in-vehicle) navigator is ordinarily arranged to provide guiding only when a vehicle is positioned on a road. Guiding is thus normally not even provided if the onboard navigator is operated outside the road such as in a parking lot, or the like to make a route searching to a destination. Therefore, as shown in FIG. 6, for example, when one""s vehicle 3 parking at a position P1 of a parking lot 2 proceeds toward a road 1 to move to a position P2 near an exit of the parking lot 2 for further going into the road 1, the driver is not able to determine to which of the right and left he/she shall turn.
On the other hand, as an onboard navigator, there are known a so-called map navigator which indicates a map picture on a display to provide route guiding and instruction, and a so-called arrow navigator which indicates only by an arrow without indicating a map. In this kind of navigators, there is known a technique for indicating the direction from the position of one""s vehicle to a destination by an icon of an arrow 4. This technique, however, performs only the route guiding regarding the roads stored in the map data for route searching purposes. It follows that, when one""s vehicle goes into the road from a point outside the road (e.g., a parking lot, a park, or the like), it was not known which way to go first.
Therefore, conventionally, it was normal practice for the driver to go into the road, for the time being, by turning to the right or to the left at his/her discretion, an ordinary guide indication by the navigator being performed thereafter. It follows that the direction actually turned is sometimes opposite to the direction to the destination. In such a case, the driver had to go to the trouble of turning back the other way.
This invention has been made to solve the above-described drawback and has an object of providing a guide indication method in an onboard navigator which enables an indication of which of the right direction and the left direction to turn when one""s vehicle goes into a road from outside the road, such as from a parking lot, or the like.
A guide indication method in an onboard navigator according to this invention in which a route guide to a destination is made by indicating an arrow on a display along a route set in advance comprises the step of guiding a turning direction of one""s vehicle at a time of going into a road from outside the road.
Thus, when one""s vehicle goes into the road from outside the road, the turning direction is known, so that one is able to smoothly travel on a searched route.
The guide indication method in an onboard navigator according to this invention further comprises the steps of: determining through a route searching outside the road as to whether one""s vehicle is in matching with any one of links of departure place; if one""s vehicle is not matching, performing a route searching for a link of departure place around one""s vehicle; and when one""s vehicle has proceeded into a position within a predetermined distance relative to an arbitrary link of departure place, guiding which of right and left directions to turn relative to a route of the arbitrary link of departure place.
Thus, when one""s vehicle goes into the road from outside the road, the most optimum route from among a plurality of links of departure place around one""s vehicle as well as the turning direction are known, so that one is able to smoothly travel on a searched route.
The guide indication method in an onboard navigator according to this invention further comprises the steps of: determining through a route searching outside the road as to whether one""s vehicle is in matching with any one of links of departure place; if one""s vehicle is out of matching, obtaining a route with a link nearest one""s vehicle serving as a link of departure place; thereafter obtaining a relationship among a position of the link of departure place, a bearing of the route, and the position of one""s vehicle; obtaining a name of the link of departure place from a data map file; and indicating a name of the road of the departure place, thereby guiding which of right and left directions to turn.
Thus, when one""s vehicle goes into the road from outside the road, the most optimum route from the link nearest one""s vehicle, the turning direction, and the name of the road of the departure place are known, so that one is able to smoothly travel on a searched route.
The guide indication method in an onboard navigator according to this invention is characterized in that the guide of the turning direction is made by an arrow or by a voice.
Thus, the turning direction is easily and accurately known.